1. Field of the Invention
The invention relates to a workpiece transfer assembly for a press of the type including a reciprocating member and a series of longitudinally spaced in-line stations wherein each station is a further progression of the workpiece forming process.
2. Description of the Prior Art
Such a transfer assembly comprises at least one horizontal carrier beam, a vertical drive system for moving the carrier beam between various vertical positions along a vertical axis on a press, at least one horizontal arm extending transversely to the carrier beam for supporting and moving a transfer bar into and out of the press, and a horizontal drive system for moving the arm into and out of the press along a transverse horizontal axis extending transversely to the carrier beam and for moving the arm along a longitudinal axis extending longitudinally and parallel to the carrier beam. The horizontal drive system to which the subject invention applies includes a pair of spaced pulleys and an endless belt entrained about the pulleys along a drive axis and a connection connecting the belt and the arm for moving the arm along one of the axes in response to movement of the belt.
In the event a problem arises within the press to prevent or interfere with normal or programmed movement of the transfer bar and/or arms that support the transfer bar, damage can occur to the horizontal drive system, particularly the electric drive motor, which can burn out if forced to stop while having drive power applied thereto.
The subject invention improves the connection between the belt and the arm for moving the arm along one of the axes in response to movement of the belt. In accordance with the subject invention, the connection is characterized by including a detent mechanism for snapping out of engagement in response to a predetermined force whereby the belt is disconnected from the arm in response to a predetermined force resisting movement of the arm by the drive system.
Accordingly, the subject invention prevents damage to the horizontal drive components, including the motor, or the arm or the transfer bar carried by the arm. This damage is prevented as the detent mechanism allows movement of the arm and transfer bar supported thereby to stop in response to a predetermined force of resistance while allowing the motor, etc., of the horizontal drive system to continue to move until it would normally stop.